My research covers many aspects of melting and crystallization in the Earth and planets, but most recently is concentrated on experimental melting and crystallization of mafic magmas at crustal pressures. A particular target has been the Kiglapait layered intrusion in Labrador and associated Labrador anorthosites. With fellow petrologists at the Five Colleges, we are now shifting our focus to the origin of syenite and trachyte, with a long-term experimental study involving undergraduate and graduate students. We are using the Five-College experimental petrology laboratory under the direction of Professor John Brady at Smith College, using graphite capsules and both synthetic and natural crystalline starting materials. We estimate that there will be as many as 50 binary, ternary, and quaternary systems of interest in this study, which is intended to discover why syenites and trachytes are so rich in feldspar relative to their presumed cotectic liquid compositions saturated with Fe-rich olivine and clinopyroxene.
Recently published research by members of this team has treated an experimental study of the cotectic trace for the Lower Zone of the Kiglapait Intrusion, and the mineralogy of the augite series in that intrusion. New papers treat the principles of multiphase Rayleigh fractionation in crystallization and melting, and the search for liquid compositions in Labrador massif anorthosites (see the short bibliography). Experimental work in progress by grad student Deb Banks McIntosh defines the phase equilibria of a model Kiglapait magma composition at pressures up to 13 kb, with coexisting spinel, garnet, and aluminous pyroxenes that break the olivine-plagioclase tie line.
Deep crustal metamorphic petrology of rare, high-temperature sapphirine granulites from central Labrador is another lively interest, in part to see if we can show for the first time the occurrence of igneous sapphirine.
Discovered Kiglapait Layered Intrusion, Labrador, used as a guide to igneous fractionation processes in the earth and planets. Discovered linear partitioning in binary solutions. Interested in mineral/melt partition coefficients; Anorthosites as guides to chemical and crustal evolution of the earth; Crystallization of terrestrial planets. Melting relations of rocks; theoretical and experimental petrology; multiphase Rayleigh fractionation. Intensive parameters of mafic magmas. Empirical magma dynamics. Petrology of sapphirine granulites. Optical mineralogy. Championship hand mowing, skiing, riding, canoeing, logging.
Related InformationShort CVBibliography of the Kiglapait Intrusion
Last updated 11 Nov 2005 |
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